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Classical Engines with Ideal Efficiency and Non-Zero Power: Is It Possible?

  • DATE: MAY 17, 2017, 01:15 PM

Academia Europaea Wrocław Knowledge Hub and Wrocław University of Science and Technology invited students, academic teachers, and citizens of Wrocław to a lecture by Prof. J. O. Indekeu entitled Classical Engines with Ideal Efficiency and Non-Zero Power: Is It Possible?

Short outline of the lecture:

A classical engine with ideal efficiency (unity for a chemical engine and Carnot for a thermal one) has zero power because a reversible cycle lasts infinitely long. However, at least from a theoretical point of view, it is possible to conceive (irreversible) engines with non-zero power that can reach ideal efficiency. Our way to do this is by replacing the usual linear transport law with a sublinear one and taking the step-function limit for the particle current (chemical engine) or heat current (thermal engine) versus the applied force. We speculate on the physical motivation for a sublinear law and a step-function law in the context of criticality and first-order phase transitions, respectively. Quantum engines are also relevant in this context but were not discussed in this talk.


Joseph Octave Indekeu, who in 2013 was awarded a Belgian Academy Prize for Science Outreach, was Head of the Department of Physics and Astronomy at KU Leuven from 2011 until 2015 ( The Department consists of 7 Research Units: Soft matter and biophysics, Nuclear physics and radiation, Semiconductor physics, Solid state physics and magnetism, Astronomy, Theoretical physics, and Physics education. At the time, the Department’s staff comprised 35 professors, 130 PhD students, 90 Postdocs, as well as 50 administrative and technical staff. The Department enjoyed a fruitful research visitation in 2011 by an international panel of experts.

While being actively involved, as a leader, in maintaining the highest standards of research, teaching, and services to the university and society throughout his Department, Joseph Octave Indekeu’s personal activities are centred around research into theoretical statistical physics, which he conducts with his team (, as well as teaching general physics and quantum physics, and popularising science by performing in a physics cabaret together with his children (

Joseph Octave Indekeu’s international profile is very well-balanced and has enabled him to establish a network of colleagues and collaborators who strive to achieve highly original and pioneering contributions to science. After his postdoctoral years at MIT, TU Delft, and RU Leiden, and shorter stays in Padova, Bristol and Oxford, he developed various seminal lines of research into wetting phenomena and interfacial critical phenomena. This, in particular, led to a novel view on surface superconductivity, which resulted the prediction of an interface delocalisation (or „wetting”) phase transition in type-I superconductors. The prediction was verified experimentally. Furthermore, in 2013, Indekeu co-investigated, along with the researchers of Imec, wetting states in nanopatterned silicon (published in ACS NANO), which has numerous applications since reliable wet cleaning of nanopatterned Si wafers is an extremely important issue in modern technology.